The health and well-being of domestic animals often depends on their access to exercise and entertainment. For many pets, both of these goals can be aided by presenting opportunities for play; dogs, for instance, are known to enjoy having balls thrown to them, and cats like to stalk and pounce on strings or other objects dragged along the floor. One particularly notable source of entertainment for animals involves climbing into and onto structures, enclosures, and the like. Doll-houses and similar constructions are sometimes provided to animals for this purpose. Likewise, many animals need hiding places for emotional well-being, and have been known to take advantage of such structures for that reason. However, doll-houses for animals can be expensive and take up space, and suffer from attrition with lengthy use. As a result, they can be infeasible for many pet owners.